With continuous development of Internet applications, information and data that a network server needs to store become more and more, and as a result, the storage capacity required for the network server continuously increases. When the internal storage capacity of the network server cannot satisfy the demand for information increase, it is required to “externalize” the storage of the network server.
In order to solve this problem, storage area networks (Storage Area Networks, SAN) are proposed in the prior art, and the SAN provides a dedicated external storage environment for the network server, makes full use of new storage hardware technologies and network technologies, so as to satisfy demands for storage, access and backup of data of large capacity and high reliability.
A fiber channel (Fiber Channel, FC) is a protocol applied the most widely in the SAN, that is, data is transmitted based on an FC network in the SAN. However, there are a large number of switches, network interface cards, and cables required for implementing the FC network, and additionally, the cost of these devices is high, so that for the FC network, the device cost is high, the maintenance is difficult, and the scalability is bad. To solve the problem, the prior art uses the FCoE (Fiber Channel over Ethernet, fiber channel over Ethernet) protocol to bear the FC protocol on the basis of the Ethernet, so as to integrate the SAN and a local area network (LAN).
When most storage arrays in a data center are PC targets (FC Target), an FCoE initiator (FCoE Initiator) is connected to a lossless Ethernet (Lossless Ethernet), and PC data is transmitted to the FC SAN through an FCoE switch (FCoE Switch), so as to finally access the FC target. However, with the development of the FCoE standard, an FCoE target (FCoE Target) emerges, and an FCoE initiator may access an FCoE Target directly through a lossless Ethernet.
In the existing FC-BB-5 (Fiber Channel Backbone Generation 5) standard, the process that an FCoE initiator establishes a communication connection with an FC target is as follows:
Step A: When an FCoE initiator is initiated, a Discovery Solicitation (discovery solicitation) message is sent by taking a destination MAC address (Media Access Control address) as an All-FCF-MACs (All-FCF-MACs is a broadcast address defined in the protocol), and a Discovery Advertisement (discovery advertisement) message is transmitted back through an FCF, so as to acquire MAC addresses of all FCFs (FCoE Forwarder, FCoE forwarder) in the current network;
Step B: The FCoE initiator selects one of the FCFs to send an FLOGI (FABRIC LOGIN, fabric login) message;
Step C: After receiving the FLOGI message, the FCF may allocate an N_Port_ID (N port identifier) to the FCoE initiator, to use it as a unique identifier of the FCoE initiator in the PC network;
Step D: The FCF adds an FC-MAP (FCoE mapped MAC address, FCoE mapped MAC address) before the N_Port_ID to use it as a virtual MAC address of the FCoE initiator, and returns the virtual MAC address to the FCoE initiator through an PLOW LS_ACC (link acceptance) message, in which the virtual MAC address amounts to 48 bits, the most significant 24 bits are the FC-MAP, the least significant 24 bits are the N_Port_ID;
Step E: The FCoE initiator sends a PLOGI NS (Port Login Name Server, port login name server) message to the FCF, so that the FCF uses a WWN (World Wide Name, world wide name), on a Name Server (name server), of the FC target that the FCoE initiator is to access to find the N_Port_ID of the FC target in the network after query, and sends the N_Port_ID to the FCoE initiator through a PLOGI NS response message;
Step F: The FCoE initiator obtains the N_Port_ID; through the FCF, the FCoE initiator, to the FC target, sends a PLOGI (Port Login, port login) message to the FC target to be accessed, then the FC target returns a PLOGI ACC (port login acceptance) message, the port login is completed, and the FCoE initiator establishes communication with the FC target through the FCF.
In the prior art, according to the process specified in the FC-BB-5 the process that the FCoE initiator establishes a communication connection with the FCoE target is implemented. However, inventors find that, in the prior art, the FCoE initiator only learns the N_Port_ID of the FCoE target, and when the FCoE initiator communicates with the FCoE target, forwarding must be performed through the FCF, and due to the forwarding operation, so unnecessary transmitting delay is caused and the processing load of the FCF is also aggravated.